Your driver will expose the highest OpenGL version your GPU supports (e.g., 4.6 on modern cards). OpenGL 2.0 is included automatically.
If you have no GPU with OpenGL support (extremely rare since 2005), you can use (very slow): opengl 2 o download
While "OpenGL 2.0 download" is a common search term, OpenGL is not a standalone software package you download like a game or a web browser. Instead, it is a (Application Programming Interface) that comes bundled with your Graphics Card (GPU) Drivers . Your driver will expose the highest OpenGL version